1. Field of the Invention
The present invention relates to a conveyor system including a support rail with travel surfaces for driven support wheels of vehicles, such as suspended or elevated trolleys or the like, with an additional rail associated with support rail for additional wheels acting on the support wheels.
2. Description of the Related Art
In conveyor systems of the above-decribed type, as disclosed in German Patent 47 42 43 and German Patent 39 05 210, springs always act on the additional wheels. Along ascending and descending paths, the additional wheels come into contact with additional rails so that the support wheels are additionally loaded in order to increase the frictional engagement thereof. By the spring mounting of the additional rails, the cost of the trolleys is increased. This is not particularly disadvantageous if only a few trolleys are used in a conveyor system. However, when a large number of trolleys are employed in a conveyor system, the additional expense for the spring mounting of the additional wheels constitutes a disadvantage, particularly when they are used only infrequently within the conveyor system, for instance when only one ascending path and one descending path are present.